Note: The citations/figures provided in the tables above have been compiled from sources over which BGS does not exercise control, and according to the prevailing understanding of the position at the time using existing methods of interpretation.
The BGS therefore gives no warranty as to the accuracy of the information or its suitability for any use. The BGS is keen to hear from visitors to this site holding a different view or interpretation of the citations/figures and we are willing to make changes where appropriate.